I don't understand why the unvaxxed became the problem when some countries, including South Korea and Japan, initially considered vaccinating only the elderly and the at risk on a voluntary basis, that is to say, there is no scientific reason why the unvaccinated should be a more dangerous pool than colonies in animals (as in 'mink farms' and else; or even in zoos, cf.
https://www.theguardian.com/us-news/2022/jan/08/snow-leopard-dies-covid-19-illinois-zoo), or again, tourists returning from a place where the wave is only at its beginning.
Some research throughout the epidemy has noticed that the superspreaders were actually quite few in comparison to the infected people. That's maybe why very few countries did serious contact tracing (Belgium is one).